1. Field of the Invention
The invention relates to a valve assembly for medical procedures.
2. Discussion of the Related Art
Valve assemblies are used in many medical procedures. More specifically, introducer sheath valves are used in a wide variety of minimally invasive and conventional surgical procedures. For example, laparoscopic and arthroscopic surgical procedures are often performed through trocar assemblies, which include introducer sheath valves.
Current introducer sheath valves generally fall into two basic categories: passive and active. A passive introducer sheath valve generally relies on the deformation of a resilient sealing body by the implement inserted through the valve to form the desired fluid tight seal. Active valves include a mechanism that moves a sealing body into contact with the traversing implement. An example of an active valve would be constructed of a housing and a tubular resilient valve carried within the housing. This valve requires a means for varying the pressure in the space within the housing but outside of the tubular valve in order to urge the resilient valve to collapse inwardly to seal around the implement.
Another example of an active valve is constructed of an elastomeric sealing body, which will maintain hemostasis by contacting a surgical implement traversing the valve over a very small contact area. The orifice is formed in the thin elastomeric membrane, which extends radially inward from a torroidal balloon having a relatively rigid outer rim and a flexible inner portion. In this example, a vacuum is applied within the torroidal balloon to pull the elastomeric membrane radially outward for implement insertion. Sealing around the implement is actuated by applying a positive pressure within the torroidal balloon expanding the balloon radially inward to block access through the valve.
While these and other valve designs are fairly tolerant of various diameters of surgical implements, all of the currently available valves have significant limitation as to the variation in diameter, variation in shape of implement and how many implements which can pass through the valve without damaging it and with optimal sealing properties. For these reasons, it would be desirable to provide improved introducer sheath valves for use in endovascular, laparoscopic and other surgical procedures. Such valves would preferably seal over a wide range of surgical implement diameters, shapes, and multiple implements without imposing the high frictional forces of known valves, regardless of cross-sectional size or shape of the surgical implement traversing the valve.
Although specifically discussed as an introducer sheath valve, the invention encompasses other applications such as bariatric port access, medical injection port, vascular access port, valve for insertion sites such as feeding tubes or dialysis access port, etc.